styles.css

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

header {
    margin: 0;
    background-color: #f8f8f8;
    box-shadow: 0px 4px 6px rgba(0, 0, 0, 0.1);
}

h1 {
    margin: 0;
    font-family: 'Montserrat', sans-serif;
    color: #333;
}

main {
    background-color: #f2f2f2;
    padding: 50px 0px;
}

article {
    margin: 10px;
    padding: 20px;
    width: calc(33.33% - 20px);
    background-color: white;
    box-shadow: 0px 4px 6px rgba(0, 0, 0, 0.1);
}

@media (min-width: 600px) {
    article {
        flex-basis: calc(50% - 20px);
    }
}

@media (min-width: 900px) {
    article {
        flex-basis: calc(33.33% - 20px);
    }
}

h2 {
    margin-bottom: 20px;
    font-family: 'Open Sans', sans-serif;
    color: #333;
}

ul {
    margin: 0;
    padding: 0;
        list-style: none;
}

li {
    margin-bottom: 10px;
    font-family: 'Open Sans', sans-serif;
    color: #555
}

form {
    background-color: #f2f2f2;
    padding: 20px;
    border-radius: 5px;
    margin-top: 20px;
}

label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
}

input[type="text"],
input[type="email"],
textarea {
    width: 100%;
    padding: 10px;
    margin-bottom: 10px;
    border: none;
    border-radius: 5px;
    background-color: #fff;
}

button[type="submit"] {
    background-color: #4caf50;
    color: white;
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

button[type="submit"]:hover {
    background-color: #3e8e41
}